fix(session-ui): expand tool error cards to full input and error

[Hona]

Failed tool cards toggled their arrow but showed nothing. The card only expanded the text after the first ": " in the error, and it never showed the tool input. Real Code Mode errors such as Invalid browser URL. … have no ": ", so the expanded view was empty.

Before (both cards clicked)	After (both cards clicked)

• When open, the error card now shows the full input and the full error message in the same two-tone console block as a normal Execute or Shell card.
  • execute: the code. shell: the command. Other tools: input JSON. Question tools: no input block.
• When the card is open, the header hides the truncated summary and subtitle (subagent links stay visible).
• Errors with no input (for example, direct shell exit notices) show the full error text, not only the part after the colon.
• Adds the Terminal / Execute failed story with the exact calls from the bug report, plus a component test.

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